This invention relates to blood sampling apparatus, and more particularly to a system for delivering a plurality of disposable cannula adaptors, each of which is formed to be retained in a holder for engagement of a cannula.
As medical science has advanced, the sampling and analysis of a patient's blood has become an important diagnostic aid. However, blood collection can also pose hazards for the person drawing blood, and therefore various devices have been developed to protect the drawer from contamination as much as possible.
U.S. Pat. Nos. 4,841,985; 4,984,580 and 5,117,837 are directed to various developments in blood drawing apparatus, and the disclosures of said patents are incorporated herein by reference. In one form of the blood drawing apparatus of such patents, a disposable cannula adaptor is employed in connection with a holder for an evacuated blood collection tube. The cannula adaptor is inserted in one end of the holder and held temporarily in place, and a blood needle is then screwed into the adaptor, with one end extending outwardly for vein puncture, and an opposite end extending inwardly in the holder for piercing a blood collection tube. After use of the holder to collect blood, the cannula adaptor and cannula are released from the holder, and disposed. The holder can be disposed, or cleaned and reused with a new cannula adaptor.
While the cannula adaptor concept of the incorporated patents provides a significant advance in blood drawing apparatus, proper delivery of the cannula adaptors, to prevent contamination and to provide easy access, remains beyond the scope of the patents.